function* gen(params) {
    // Generator函数中yield关键字不会自动执行，必须通过next方法执行
    const res = yield fetch("http://123.57.109.30:3999/api/provincesList");
    console.log(res);
}
const g = gen();
const res = g.next();
res.value.then((response) => response.json()).then((data) => g.next(data));

export default function App(params) {
    return <div>App</div>;
}
